The Composition of Saturn’s Rings
Abstract The origin and evolution of Saturn’s rings is critical to understanding the Saturnian system as a whole. Here, we discuss the physical and chemical composition of the rings, as a foundation for evolutionary models described in subsequent chapters. We review the physical characteristics of the main rings, and summarize current constraints on their chemical composition. Radial trends are observed in temperature and to a limited extent in particle size distribution, with the C ring exhibiting higher temperatures and a larger population of small particles. The C ring also shows evidence for the greatest abundance of silicate material, perhaps indicative of formation from a rocky body. The C ring and Cassini Division have lower optical depths than the A and B rings, which contributes to the higher abundance of the exogenous neutral absorber in these regions. Overall, the main ring composition is strongly dominated by water ice, with minor silicate, UV absorber, and neutral absorber components. Sampling of the innermost D ring during Cassini’s Grand Finale provides a new set of in situ constraints on the ring composition, and we explore ongoing work to understand the linkages between the main rings and the D ring. The D ring material is organic- and silicate-rich and water-poor relative to the main rings, with a large population of small grains. This composition may be explained in part by volatile losses in the D ring, and current constraints suggest some degree of fractionation rather than sampling of the bulk D ring material.
Authors
- Matthew M. Hedman (ORCID: https://orcid.org/0000-0002-8592-0812)
- G. Filacchione (ORCID: https://orcid.org/0000-0001-9567-0055)
- W. L. Tseng (ORCID: https://orcid.org/0000-0001-7322-3801)
- P. R. Estrada (ORCID: https://orcid.org/0000-0002-1132-5594)
- J. H. Waite (ORCID: https://orcid.org/0000-0002-1978-1025)
- C. Ferrari
- Kelly E. Miller (ORCID: https://orcid.org/0000-0001-5657-137X)
- Kévin Baillié (ORCID: https://orcid.org/0000-0002-2120-6388)
- P. D. Nicholson
- Amanda Hendrix (ORCID: https://orcid.org/0000-0002-0435-8224)
- R. E. Johnson (ORCID: https://orcid.org/0000-0001-7798-5918)
- Julianne I. Moses (ORCID: https://orcid.org/0000-0002-8837-0035)
- Hsiang‐Wen Hsu (ORCID: https://orcid.org/0000-0002-5478-4168)
- Jeffrey N. Cuzzi (ORCID: https://orcid.org/0000-0003-0553-1436)
- M. Ciarniello (ORCID: https://orcid.org/0000-0002-7498-5207)
- Zhimeng Zhang (ORCID: https://orcid.org/0000-0002-1558-4948)
Institutions
- California Institute of Technology (US)
- Ames Research Center (US)
- Southwest Research Institute (US)
- Centre National de la Recherche Scientifique (FR)
- Space Science Institute (US)
- Planetary Science Institute (US)
- National Taiwan Normal University (TW)
- Institut de physique du globe de Paris (FR)
- University of Idaho (US)
- University of the Virgin Islands (VI)
- Université Paris Cité (FR)
- Cornell University (US)
- Université de Lille (FR)
- Université Paris Sciences et Lettres (FR)
- Sorbonne Université (FR)
- Institute for Space Astrophysics and Planetology (IT)
- Laboratory for Atmospheric and Space Physics (US)
- University of Virginia (US)
- Institut de Mécanique Céleste et de Calcul des Éphémérides (FR)
- University of West Florida (US)
Publication Details
- Journal
- Space Science Reviews
- Published
- 2024-09-01
- DOI
- https://doi.org/10.1007/s11214-024-01104-y
- Citations
- 10
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 3.32
Funders
- National Aeronautics and Space Administration
- Istituto Nazionale di Astrofisica